1. Field of the Invention
The present invention relates to an electronic still camera, and more particularly, to an electronic still camera designed to record on a memory card an audio signal in addition to an image signal.
2. Related Background Art
Electronic still camera systems which employ as a recording medium a floppy disk for recording an image signal and an audio signal are known. In such a system, an audio signal is recorded on a plurality of tracks on the video floppy disk in a compressed form.
To compress the audio signal, an analog audio signal is converted into a digital signal by means of a clock having a frequency of about 10 kHz, and the resultant digital audio signal is then temporarily stored in a large-capacity semiconductor memory. Thereafter, the digital audio signal is read out from the semiconductor memory by means of a clock having a frequency of about 7 MHz and then converted into an analog audio signal again and recorded on the video floppy disk.
In the conventional electronic still camera of the above-described type, since image and sound are recorded on and reproduced from a video floppy disk, a video floppy disk rotation mechanism, a large-capacity semiconductor memory, a D/A converter and so on are required, increasing the overall size, weight, power consumption and production cost of the electronic still camera.
Furthermore, a digital image signal and an analog audio signal must be recorded on separate tracks on a video floppy disk. Consequently, when the image signal and the audio signal are to be recorded on the video floppy disk at the same time, a recording head must be moved relative to the video floppy disk for writing signals on separate tracks. This requires a complicated timing control.